A base station in a communication system may perform channel estimation for a physical uplink data channel by using a DMRS (demodulation reference signal, demodulation reference signal) sequence sent by a UE (User Equipment, user equipment). The base station performs demodulation on data information carried on the physical uplink data channel by using a channel coefficient that is estimated by using the DMRS. The demodulation reference signal transmitted by the user equipment is a sequence known to both the base station and the user equipment. In addition, a UE served by the base station needs to transmit a demodulation reference signal when uplink data is transmitted. Demodulation reference signals transmitted by different UEs are orthogonal. Orthogonality of the demodulation reference signals transmitted by different UEs may be implemented by manners of frequency division multiplexing, time division multiplexing, code division multiplexing, or different cyclic shifts.
A manner of semi-persistent scheduling may be adopted for uplink data scheduling or downlink data scheduling in the communication system.
In the prior art, when uplink data transmission is performed by adopting the semi-persistent scheduling manner, different user equipments cannot perform data transmission on a same time and frequency resource, which reduces spectrum utilization efficiency.